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Cowboys DE Kneeland’s Stage 1 CTE Diagnosis Prompts Safety Warning

7/7/2026

Summary

Kneeland CTE Diagnosis

Dallas Cowboys defensive end Marshawn Kneeland was diagnosed with Stage 1 CTE after his suicide on Nov. 6, 2025.
Boston University’s CTE Center confirmed the Stage 1 diagnosis via post-mortem brain analysis.
The 24-year-old died of an apparent self-inflicted gunshot after a police chase for a traffic violation.
His family released the findings, prompting Dr. Ann McKee and Chris Nowinski to warn that protocols have not reduced CTE risk and demand impact-reduction measures.

Summary

Kneeland Deadly Pursuit

A trooper said Kneeland’s car topped 145 mph in the Nov. 5-6, 2025 pursuit, after which he fled and was found dead.
He had crises, including a 2020 firearm surrender and a railroad-track incident where he hoped train would hit him.
Wendy Kneeland died in February 2024, leading him to wear a necklace with her ashes.
Catalina Mancera gave birth to son Makhai on June 11, 2025, making him a father before death.

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Kneeland CTE Diagnosis

Dallas Cowboys defensive end Marshawn Kneeland was diagnosed with Stage 1 CTE after his suicide on Nov. 6, 2025.
Boston University’s CTE Center confirmed the Stage 1 diagnosis via post-mortem brain analysis.
The 24-year-old died of an apparent self-inflicted gunshot after a police chase for a traffic violation.
His family released the findings, prompting Dr. Ann McKee and Chris Nowinski to warn that protocols have not reduced CTE risk and demand impact-reduction measures.

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